I could not bring Monday's Guardian into my house. I have a problem with pictures of hanged, broken-necked men looking at me across the freshly squeezed orange juice. I would have the same trouble with limbs being chopped off, children mangled by dogs, and the new America cult of police CCTV footage of murders, muggings, rapes and car crashes. When the government sells the broadcasting rights to John Reid's 100 Best ID Cards and Patricia Hewitt's Most Ghoulish NHS Record of the Week, I shall also turn my head away.

Do I have a queasy stomach, a morbid fear of the noose and a bourgeois aversion to the world as it really is? Should I retreat to a monastery where man's inhumanity to man can be contemplated in the abstract? Perhaps I have been at this game too long and should take Voltaire's advice to cultivate my garden.

I think not. Taste is what I like, you hate and other people want the government to ban. It has long been a marketing maxim that if you can chart the map of taste, the world will beat a path to your door. You will have found the secret of desire, acquisitiveness and profit.

To the artist, taste is a meaningless concern. Art's role is ceaselessly to "push back the boundary of taste". Wagner is redesigned with naked maidens. Actors have sex on screen and presumably one day on stage. Comedians are dreadfully rude about Tony Blair. Little damage is done as long as the Arts Council money keeps flowing. I remember a striptease dancer demanding her right "as an artist" to perform at the Institute of Contemporary Arts. The director and staff were terrified of being seen as censors and let her go ahead. The show was a total con, but the takings were great.

The mass media have a less easy time. They must sell their wares in a series of niche markets. Every newspaper and broadcaster has in-house rules of taste unrelated to law. Dead bodies are rarely pictured if next-of-kin might see the corpse, which is why photographs of the Hillsborough football tragedy caused such offence. Intrusion on privacy is governed by rules no less real for being often breached. Barely a week passed during the celebrity of Princess Diana when an editor did not agonise over what not to publish, incredible though this seems given what did appear. The Guardian prints four-letter words while the Times does not. The Sun's glorious boobs are the Telegraph's unsightly decolletage.

Taste changes. The handling of race on television comedy in the 1960s would be inconceivable today. The BBC is in constant turmoil over bad language and the "watershed". Like a newspaper, it is "in the home" and available for all the family to see. Yet the Today programme assumes parents are happy to discuss anal sex with their children over breakfast. I imagine that executives deliberated this decision at length. These things matter to people.

Conventional wisdom holds that this edifice of rule-bound censorship is collapsing. The editor has been demystified and disempowered. All the world can peddle its wares on the internet without let or hindrance. Each is his own artist, novelist, reporter, diarist, columnist and, above all, editor. The carefully written and processed article enjoys no higher status than the blog responses that cling to its feet. Why listen to steam radio when you can wander the backstreets of YouTube and MySpace and watch real people do real things. Alexander Pope was right: such random chance is "direction which thou canst not see,/ All discord, harmony not understood". Or as Donald Rumsfeld put it, stuff happens.

To say that the internet is giving formal journalism a nervous breakdown is an understatement. If palm-sized mobiles can intrude on every privacy and hackers break into every computer, who are newspapers to remain as haughty intermediaries? If I do not want Saddam Hussein's head lolling across the corn flakes, I need not log on to it (pending the advent of 1984). Every two-bit terrorist or overnight exhibitionist has the freedom of the web, and I can always press "close" and "delete".

I can customise my own news site and be my own censor. Nothing need ever offend me again. I can firewall the viruses and bypass the spam. If my alter ego senses a four-letter word, a maimed corpse, a climate-change article or an "issues agenda" heading my way, it can send out electronic chaff. When all content is user-generated, the consumer is king and editors are toast. Journalists are clinging to the wreck of the Medusa, battered survivors pondering cannibalism or death.

I disagree. Some years ago there was a brief craze for online novels in which readers were allowed to write their own endings. It was hailed as "reader empowerment" - and it was drivel. Like the sing-your-own Messiah at the Royal Albert Hall, it was fine so long as nobody needed a paying audience. I do not recall whether the fad moved to the theatre, with audiences summoned on stage to create a spontaneous denouement. The London Symphony Orchestra never handed its violins to the front row of the stalls.

Whatever the borderline between amateur and professional, skill and artistry, some things are very difficult to do, and most people will admire and pay those who do them. Every creative talent comes with unseen baggage, directors, designers, stage-setters, publishers, editors and coaches. No art is without effort, and the effort is collective. If the electronic marketplace becomes devoid of copyright, producers will devise ways of protecting and "monetising" their appeal. Pulp fiction still seems to be thriving.

The internet has certainly torn up the media of communication pioneered by Gutenberg and Caxton, Marconi and Reith. The anarchist in me is attracted by the sovereignty of the mob. I like to see the market, the audience, hitting back occasionally - even if it does so from the Tower of Babel. Shakespeare had to contend with his groundlings and La Scala with its claque.

But rulebooks there will always be. The popular scientist EO Wilson explained the cultural genetics that guide our myriad responses to group stimuli. Embedded in our DNA, they govern everything from artistic sensibility to habit, style and forms of pleasure. In matters of taste, these genes demand frameworks of trust, whether the proclaimed intermediary be a priest or a fashion editor.

I trust certain writers, directors, composers, artists, even newspapers, to widen my horizons without revolting me. Between their transmitting and my receiving is a zone of faith. That is why, however worldwide the web, there will never be a "blog-standard" newspaper. I need to trust a news-gatherer to adhere to known standards of veracity and taste, or my own judgment will go haywire. Those with no one to trust are not to be trusted.

There is no substitute for a disciplined, rule-bound, edited news-gatherer any more than there is for a formal theatre, movie-maker or publisher. Marshall McLuhan's "the medium is the message" will not find its apotheosis in the internet. The message transcends the medium and always will. The fact that a reader's taste can sometimes be shocked shows the power of the trust on which it is normally based.